Add another vote for the 308. Tough to beat, particularly if the use of factory ammo is a requirement. A buddy gave me a box of Nosler Custom 165 BT's that kept 5 shots in a 2" circle at 500 yards! They were moving at 2800 FPS with an ES of 12FPS. This is as good as any of my hunting reloads. If there was ever a possibility of stretching to 1000 yards, I'm also a proponent of the 6.5's, being partial to the 6.5x284. Very low recoil, great accuracy and ballistics, and with 140's, drops deer sized game at long range like a magnum class cartridge. For hunting proposes, barrel life is a moot point. No different than most calibers that perform like this on game at 1000 yards. iMHO.

I've got about 10 calibers but day in day out, hunting what I hunt and realistically my distance is under 500 yards it's 308 all the way. Having so much ammunition and good stuff available it is hard not to have at least 1 308 in the safe. It effectively replaces the 06, the military established that. even 06 ammunition is less prevalent in gun shops today. Check out any manufacturer and look at the size of the 308 line compared to anything except 22lr. Love the 308.

I see alot of guys voting 308 and alot voting 6.5's. Truth is you can't go wrong either way. I have custom rigs in 308 and 6.5 X 47 Lapua and BOTH hammer. Both calibers have Lapua brass (best on the market IMO), both are VERY accurate calibers and easy to find a load for. The 6.5 will have less recoil obviously but the 308 is easy to get factory ammo for but the 6.5 lapua is not. I've shot deer with both with VLD's and same results, dead deer.....lol.....Lapua brass is much cheaper for the 308 than the 6.5 and lapua is the only one that makes brass for 6.5 X 47 round as far as I know compared to everyone makes brass for the 308. I shoot both at 600 yards often and they are both plenty accurate. With all that being said, I would probably stick with the 308 as much as i like the 6.5.

I agree with Speck. Having now got both my .308 and 6.5-284 RPA custom rifles in use, out to 600 yards they will both put 10 shots in the bull, most being inners depending on me. However the 308 is much cheaper to run and it is easier to obtain brass, only Lapua for the 6.5-284. 900 yards plus then the 6.5-284 has the edge. Consider twist rate and bullet weight carefully, I use 168-175 grain bullets with a 1-10 twist rate.

The thing that the 6.5 has going for it is the very high B.C. bullets that's mostly because it was mostly a European caliber for years and they tend to look and shooting a little differently than North Americans. In North America we tend to go for light and fast bullets and give up a lot in B.C.

That's not entirely correct. In Sweden and Norway the 6.5x55 has been the military standard cartridge throughout most of the 20th century. Since rifles and ammunition weren't as inexpensive as they are now, the standard issue rifles, which every Home Guard member took home after his conscript service, were used for hunting too. Moose are pretty big animals, to achieve suffiecient penetration out of the barely adequate but common 6.5x55 heavy, slow bullets were required, since there was no bonded core technology available. Partitioned core bullets were often too expensive for the majority of hunters too.
The heavy bullets were all of round nose design, bc was never considered when designing european big game hunting bullets back then.
The argument that the 6.5x55 has to be a good moose/big game cartridge since it's been used in scandinavia for so long a time, which you usually read in american not so much in european forums, is not valid. The 6.5x55 has been used because it was the most commonly available cartridge, not because it was better than more reasonable choices (8x57, 9.3x57 -62) and was adapted to it's role by using heavy round nose bullets. It's still being used because it has been used traditionally.
The 6.5x55 is a neat little cartridge, pretty good on european boar, roe deer &c, which usually weigh less than 150#, but it's far from being a good big game cartridge.

To the point of heavy european bullets, they have always been developed for terminal ballistic purposes. When external ballistics were an issue, for example in mountainous regions on goats and sheep hunts, fast lightweight bullets were used too. For example the 6.5x68 was developed for this purpose using bullets in the 100gr range.

Sorry for the rant, I know it's neither applicable to the threads topic, the 6.5x55 is perfectly appropriate for the intended use, nor completely to north of 53's post.